Diferencias solana-­umbría en la temperatura en los escarpes del cañón del río Duratón (Segovia) y su incidencia en los procesos geomorfológicos activos

Reunión Nacional de Geomorfología (15ª. 2018. Palma de Mallorca). - Texto en español con resumen en inglés y palabras claves en inglés y españolThis work analyzes the variations and differences of temperature that take place inside the rocky scarps of canyons, exposed to contrasted orientations, suntrap and shady. To this end, an experimental study was carried out on the scarps of the Duraton river canyon (Segovia, Central Spain). The experimental procedure, which was carried out between the end of December 2009 and the middle of November 2013, consisted in the placement of two temperature data‐logger (model HOBO Pendant) inside small hollows or taffoni of the rock, a few centimeters from the surface and completely protected from the influence of the ambient temperature. The first one was installed in the north exposure (shady scarp), while the second in southern exposure (suntrap scarp). Likewise, another temperature data-logger was installed to monitor the air temperature in a nearby village. The results show the absence of temperatures below 0ºC both in the scarp facing north (shady) and in the south oriented (suntrap), even though the absolute minimum temperatures of the air were quite low (up to ‐13.1ºC). Nevertheless, appreciable differences are observed in both exposures related especially to the extreme thermal amplitude.Departamento de Geografía, Universidad Complutense de Madrid, EspañaInstituto Geológico y Minero de España, Españ

Permafrost distribution modelling in the mountains of the Meditterranean: Corral del Veleta, Sierra Nevada, Spain

A statistical model for automated mapping of the spatial distribution of permafrost in the area of Corral del Veleta in south-east Spain (37°03′N. 3°22′W: 3398 m a.s.l.) was developed and applied. The model uses a relationship between permafrost occurrence as indicated by BTS measurements, and variables such as altitude, solar radiation and summer snow cover. The model was implemented within a geographical information system (GIS) and determines the spatial distribution of probable permafrost in Corral del Veleta. Validation was achieved by comparing the predicted permafrost distribution with the results of recent fieldwork, such as geomorphic mapping, geophysical soundings and ground temperature logging

Use of Remote Imagery to Analyse Changes in Morphology and Longitudinal Large Wood Distribution in the Blanco River After the 2008 Chaiten Volcanic Eruption, Southern Chile

The 2008 Chaitén volcanic eruption generated significant changes in the channel morphology and large wood (LW) abundance along the fluvial corridor of the Blanco River, southern Chile. Comparisons of remote sensing images from the pre-eruption (year 2005) and post-eruption (years 2009 and 2012) conditions showed that in a 10.2km long study segment the Blanco River widened 3.5 times from 2005 to 2009, and that the maximum enlargement was nine times the original width. Changes in channel width were lower between the years 2012 and 2009. The sinuosity and braiding indexes also changed between 2005 and 2009. After the eruption the channel sinuosity was higher and specific river reaches developed a braided pattern, but by 2012 the channel was recovering pre-eruption characteristics. Huge quantities of LW were introduced to the study segment; individual LW per km of channel length were 1.6 and 74.3 in 2005 and 2009, respectively, and more than 30 log jams km-1 were observed in the year 2009. Between 2009 and 2012 the quantity of LW was very similar. Statistically significant relationships were found between the number of log jams and channel sinuosity and between the number of pieces of large wood with sinuosity and channel width. Wood was highly dynamic between 2009 and 2012: 78% of individual pieces and 48% of log jams identified in the 2009 image had moved by 2012. Finally the supervised classification of imagery associated with ArcMap tools was tested to identify large woo